Jianghua Zheng

Campus Guidance System for International Conferences Based on OpenStreetMap

We present a web-based, multi-lingual, campus guidance system with emphasis on pedestrian navigation aimed at providing support for delegates attending International Conferences at the National University of Ireland Maynooth (NUIM) campus. A special campus guidance system could improve the logistics of the conference and potentially attract more delegates to the conference. The Cloudmade Web Map Lite API which uses OpenStreetMap has been used for creating this interface. The system generates shortest pedestrian paths using both outdoor pavements and indoor corridors between various buildings and points of interests (POI). For visual assistance in pedestrian navigation geotagged images are used along the path at certain points in the route, such as road intersections, when the user needs to get their orientation correct. The interface is currently available in both English and Chinese language.

Assessing the Completeness and Positional Accuracy of OpenStreetMap in China

OpenStreetMap (OSM) has been successfully applied all around the world, especially in developed western countries, but this is the first study of the quality of OSM data in China. Two data quality elements, completeness and positional accuracy, were chosen to conduct the assessment via a comparison against Baidu datasets. This chapter quantitatively depicts some characteristics of the distribution of OSM data based on the density of line and point features. The analysis showed that 71 % of the OSM data was less detailed than the Baidu datasets, but on average 66 % of OSM data was accurate. The OSM data for Beijing and Shanghai is most complete with high positional accuracy. Overall coverage was extremely poor, as more than 94 % of the country consisted of ‘incomplete regions’ (regions with few or no data). However, OSM data has grown quickly, according to a comparison of three years, 2011 to 2013. More interestingly, OSM contained more detailed information in some poor areas, which could be an improvement over datasets provided for normal users by commercial or governmental agencies.

Spatial Characteristics of Walking Areas for Pedestrian Navigation

We consider how to handle open walking areas in pedestrian navigation applications. Walking areas are a key type of feature which is a major difference between networks of pedestrian navigation and that of road vehicle navigation. Up to recently, little work has been carried out on these features though they are important to route planning algorithm design and path representation for pedestrian navigation. Characteristics of walking areas are classified into three types with orthogonal attributes, including the character of boundaries and entrances, concavo-convex characteristics of shapes and the presence and numbers of islands. The possible combinations are identified and general solutions proposed. Future work including the extension to 3D navigation in buildings and trials in mobile applications are proposed.

Design and Implementation of Campus Spatial Information Service Based on Google Maps

Using the programmable interfaces provided by Google Maps, we create a campus spatial information service system. It uses free high resolution remote sensing images as the base map and it adopts open source software and function components. Making full use of the network data and combining Google Maps and MySQL database, it provides users with rich and interactive information such as the picture, description, link and the useful measurement tool. With a breakthrough compared with the traditional system which is manager-oriented and closed, the system uses the current prevalent B/S model and absorbs the Mashup idea on the platform architecture design .These expand the scope of service people and reduce the developing difficulties and cost remarkably. The system integrates some promising key technologies of Web2.0 and pushes forward the applying of Public Participate GIS. All these make better service of personalized and humanistic digital campus. Keywords-GoogleMaps API;digital campus;open source;spatial information service

Nowhere to Invade: Rumex crispus and Typha latifolia Projected to Disappear under Future Climate Scenarios

Future climate change has been predicted to affect the potential distribution of plant species. However, only few studies have addressed how invasive species may respond to future climate change despite the known effects of plant species invasion on nutrient cycles, ecosystem functions, and agricultural yields. In this study, we predicted the potential distributions of two invasive species, Rumex crispus and Typha latifolia, under current and future (2050) climatic conditions. Future climate scenarios considered in our study include A1B, A2, A2A, B1, and B2A. We found that these two species will lose their habitat under the A1B, A2, A2A, and B1 scenarios. Their distributions will be maintained under future climatic conditions related to B2A scenarios, but the total area will be less than 10% of that under the current climatic condition. We also investigated variations of the most influential climatic variables that are likely to cause habitat loss of the two species. Our results demonstrate that rising mean annual temperature, variations of the coldest quarter, and precipitation of the coldest quarter are the main factors contributing to habitat loss of R. crispus. For T. latifolia, the main factors are rising mean annual temperature, variations in temperature of the coldest quarter, mean annual precipitation, and precipitation of the coldest quarter. These results demonstrate that the warmer and wetter climatic conditions of the coldest season (or month) will be mainly responsible for habitat loss of R. crispus and T. latifolia in the future. We also discuss uncertainties related to our study (and similar studies) and suggest that particular attention should be directed toward the manner in which invasive species cope with rapid climate changes because evolutionary change can be rapid for species that invade new areas.

A 2-D ESPO Algorithm and Its Application in Pedestrian Path Planning Considering Human Behavior

A 2-D Euclidean shortest path with obstacles (ESPO) algorithm for pedestrian navigation is developed. ESPO is a classical algorithm in the field of computational geometry. We describe some common ESPO algorithms and discuss their application in pedestrian shortest path determination based on the generation of a network of paths within a polygon with interior obstacles. This algorithm can be applied to pedestrian navigation in open spaces, such as squares, parks and big halls. Path generation is based on the Dijkstra algorithm, which is extended to solve the path planning problem not only for path and road networks but also for open spaces. The algorithm takes human preferences based on walking conditions into account and can find different paths with minimum cost for different conditions. The results of this approach are illustrated through an experimental system. Further work to integrate the algorithm into a practical pedestrian navigation system is proposed.

A PostGIS-based pedestrian way finding module using OpenStreetMap data

Open source GIS (OSG) is a fast developing field. When OSG is combined with Web2.0 and Service Orientated Architectures (SOA) technologies and more applications of Public Participation GIS, it has many advantages over commercial GIS software. Despite this, OSG still needs more improvement in terms of stability and functional integrity. In order to build more robust, more practical, and more functional LBS applications, this research investigates pedestrian-orientated wayfinding, with special requirements as its study topic. We describe some Web 2.0 routing APIs which can be easily used to provide general shortest path planning. However, these APIs cannot provide guidance services for specific user groups with special requirements, such as tourists in small towns. We take Maynooth as case-study. Maynooth is the only University town in Ireland with a population of approximately 20,000. This research uses OpenStreetMap (OSM) as spatial data source. OSM contains very spatially rich dataset. It is stored and managed in PostGIS/PostgreSQL. Through previous work on LBS applications using the CloudMade Routing API and OSM data, we present a Java-based wayfinding module implementing a restricted area version of Dijkstra algorithm. A set of native PostGIS spatial functions are used to improve performance of the routing algorithm. Results from our wayfinding algorithm are presented and compared with those obtained by using the CloudMade Routing API. Our results are promising and show that this special version of Dijkstra algorithm can take advantage of the spatial data stored in OSM. This work provides a base to build more effective pedestrian wayfinding algorithms which can be implemented in open source software and open APIs. This approach provides a feasible and economical LBS solution for small towns, villages and tourism regions outside larger cities.

The canopy rainfall interception in actual and potential distribution of Qinghai spruce (Picea crassifolia) forest

Abstract Interception is one of the most underestimated processes in hydrological cycle in arid and semiarid regions. In Qilian Mountains of northwestern arid and semiarid China, the Qinghai spruce (Picea crassifolia) forest plays an important role in the hydrological cycle of the inland Heihe River basin. The historical disturbance of Qinghai spruce forest has resulted in various ecological problems. In order to realize the sustainable development of Heihe River basin, the Chinese government implemented restoration practices for Qinghai spruce in the past three decades. In this study, we estimated the rainfall interception in the actual and potential distribution of Qinghai spruce forest. Some of the important findings include: (1) The interception ratio of rainfall events ranged from 11-51% with a mean value of 27.02%; (2) Totally, 147 Mt of rainfall is intercepted by canopy of actual Qinghai spruce forest, in the projected potential distribution of the forest, totally 407 Mt of rainfall will be intercepted.

Which one is the best: The interpolation methods comparison on average annual temperature in Xinjiang from 1951 to 2013

This paper tried to find the best interpolation method for Xinjiang average annual temperature estimation based on exploratory data analysis and 9 spatial interpolation methods comparison. The research used part of annual data set of Chinese terrestrial climatic data from 1951 to 2013 to evaluate Xinjiang average annual temperature, which contained data from 64 meteorological stations in Xinjiang and 11 ones in Gansu and Qinghai, which are nearby provinces. The results show that: 1) the SK method is the best method for the spatial interpolation of temperature in Xinjiang. The second best is the LPI method, and the third is the CRS method. 2) Compared with other methods, the SK method has obvious advantages. The RMSE of SK method is smaller 0.21°C than LPI, and 0.274°C less than CRS; The MBE of SK is less 0.19 and 0.217 than LPI and CRS respectively. The correlation coefficient is higher 0.032 and 0.059 respectively compared with LPI and CRS.

Spatial distribution of rodent pests in desert forest based on UAV remote sensing

The severe rodent damage in Gurbantunggut desert forest may result in eco-environment destruction and desertification acceleration. However, little is known concerning the level of rodent hazard, spatial distribution and regularity of outbreak. This paper approached to use high-resolution imagery (TDOM and DEM) provided by Unmanned Aerial Vehicles (UAV) for rodent pests monitoring in desert forest. The distribution of rat-holes was extracted from TDOM images, then rat-hole density were calculated for evaluating the rodent hazard degree in the study area. Lastly, topographic factors of slope gradient, slope aspect, elevation were calculated using DEM. Spatial and statistical analysis methods were used for it. The results demonstrated that Rhombimys opimus mainly distributed in the elevation of 432.5~437.5m, low slope areas of 0~15°, low RDLS of 0~0.25m, and shady slope of fixed and semi-fixed sand with well-growth plants by “island” mousehole groups. This paper validated the availability of UAV technique for dynamic monitoring rodent pests in desert forest, and laid a critical foundation for further study.